Submission #129656

#	Time	Username	Problem	Language	Result	Execution time	Memory
129656		qkxwsm	Collapse (JOI18_collapse)	C++14	0 / 100	191 ms	33132 KiB

collapse

#include <bits/stdc++.h>
#include "collapse.h"

using namespace std;

template<class T, class U>
void ckmin(T &a, U b)
{
	if (a > b) a = b;
}

template<class T, class U>
void ckmax(T &a, U b)
{
	if (a < b) a = b;
}

#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)
#define SZ(x) ((int) (x).size())
#define ALL(x) (x).begin(), (x).end()
#define INF 1000000007
#define LLINF 2696969696969696969
#define MAXN 400013
#define MAGIC 521

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;

int N, Q;
vi ans;
vector<array<int, 4> > events;
int die[MAXN];
vi ord, cand;
vi ch[MAXN];
map<int, int> rec[MAXN];

struct dsu
{
	int dsu[MAXN], siz[MAXN];
	vi edits;
	void init()
	{
		FOR(i, 0, N)
		{
			dsu[i] = i;
			siz[i] = 1;
		}
	}
	void rollback()
	{
		for (int x : edits)
		{
			dsu[x] = x;
			siz[x] = 1;
		}
		edits.clear();
	}
	int get(int u)
	{
		if (u == dsu[u]) return u;
		int v = get(dsu[u]);
		edits.PB(u);
		dsu[u] = v;
		return v;
	}
	bool merge(int u, int v)
	{
		u = get(u); v = get(v);
		if (u == v) return false;
		if (siz[u] > siz[v]) swap(u, v);
		siz[v] += siz[u];
		dsu[u] = v;
		return true;
	}
};

dsu D[2];

bool cmp(int a, int b)
{
	return events[a][2] < events[b][2];
}

void proc(int l, int r)
{
	//build the set of edges now!
	D[0].init(); D[1].init();
	cand.clear(); ord.clear();
	FOR(i, 0, N)
	{
		ch[i].clear();
	}
	FOR(i, l, r + 1)
	{
		if (events[i][1] == 2)
		{
			ord.PB(i);
		}
	}
	sort(ALL(ord), cmp);
	FOR(i, 0, l)
	{
		if (events[i][1] != 0) continue;
		int u = events[i][2], v = events[i][3];
		if (die[i] <= r) cand.PB(i);
		else
		{
			ch[v].PB(u);
		}
	}
	int cc = 0, cp = 0;
	for (int p : ord)
	{
		int u = events[p][2], qid = events[p][3], t = events[p][0];
		while(cp <= u)
		{
			cc++;
			for (int v : ch[cp])
			{
				if (D[0].merge(cp, v)) cc--;
			}
			cp++;
		}
		int res = cc;
		for (int x : cand)
		{
			int v = events[x][2], w = events[x][3];
			if (die[x] > t && w <= u)
			{
				v = D[0].get(v); w = D[0].get(w);
				if (D[1].merge(v, w)) res--;
			}
		}
		FOR(j, l, p)
		{
			if (events[j][1] != 0) continue;
			int v = events[j][2], w = events[j][3];
			if (die[j] > t && w <= u)
			{
				v = D[0].get(v); w = D[0].get(w);
				if (D[1].merge(v, w)) res--;
			}
		}
		D[1].rollback();
		ans[qid] += res;
	}
	return;
}
void solve()
{
	FOR(i, 0, N) rec[i].clear();
	FOR(i, 0, SZ(events))
	{
		if (events[i][1] == 2) continue;
		if (events[i][1] == 0)
		{
			rec[events[i][2]][events[i][3]] = i;
			die[i] = SZ(events);
		}
		else
		{
			die[rec[events[i][2]][events[i][3]]] = i;
		}
	}
	for (int i = 0; i < SZ(events); i += MAGIC)
	{
		proc(i, min(i + MAGIC, SZ(events)) - 1);
	}
}
vi simulateCollapse(int n, vi t, vi x, vi y, vi w, vi p)
{
	N = n; Q = SZ(w);
	ans.resize(Q);
	FOR(i, 0, SZ(t))
	{
		if (x[i] > y[i]) swap(x[i], y[i]);
		events.PB({i, t[i], x[i], y[i]});
	}
	FOR(i, 0, Q)
	{
		events.PB({w[i], 2, p[i], i});
	}
	sort(ALL(events));
	FOR(i, 0, SZ(events))
	{
		events[i][0] = i;
	}
	//hm ok each edge has a birth and death time.
	solve();
	for (auto &e : events)
	{
		if (e[1] == 2)
		{
			e[2] = N - 2 - e[2];
		}
		else
		{
			e[2] = N - 1 - e[2];
			e[3] = N - 1 - e[3];
			swap(e[2], e[3]);
		}
	}
	solve();
	return ans;
	//event: disconnect u -> v, connect u -> v, ask qid x pos y: so you store time, typ, who it happens to
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 30
• Subtask 3: 0 / 30
• Subtask 4: 0 / 35